I have what sounds like an exhaust leak on cold starts. After a few minutes it goes away. A couple of guys on here said that it was normal and is the cats warming up. Has anyone heard of the manifolds possibly having a leak?

 

It is normal, but it's not the cats, it's change in cam timing to get more air in the exhaust so the cats heat faster without needing an old-school air pump.

 

You should hear my car start when it's -30 out. Sounds like a diesel at first.

 

That must sound crazy

 

have you done any exhaust work?

 

No, I haven't. I did notice on the driverside there is a flex piece on the exhaust right after the cat. It seems to be ripped. I believe the leak is coming from there. I'm hearing the noise now well after its warm. I am looking into the Invidia Q300 cat-back exhaust.